AN201
V1.2 | Page 10/92
status(that is normal). When the transmission is needed, the rising edge is triggered to enter the
transmission status. After transmitting, PC1 is set to 0 and lasts more than 20ms (TOFF time), and RF
automatically exit from the Tx mode to enter the low power consumption status.
6. In this mode, the low power internal pin processing, PC1/SDIO is set to 0 output, PC2/SCLK, PC3/CSB,
and PC0/RFDIN are set to high resistance input.
2.3 Advanced Configuration Mode
When users need to achieve more functions and higher performance, such as: the target working frequency is
868MHz, the chip automatically sends packets in the transmission process, and so on, and they need to use
the advanced configuration mode. In this mode:
Select more frequency multiplication ratio coefficients to achieve the frequency range coverage of
240MHz ~ 960MHz.
Release the MCU to do more work (In the Direct mode, this process takes up the MCU resource) by
filling the FIFO and automatically sending the message (repeatedly, multiply and periodically).
Support the more accurate Tx rate, and the accuracy is determined by the crystal. It is quite accurate
(in the Direct mode, the speed is controlled by the MCU software, and the accuracy depends on the
software and internal RC).
Support the voltage detection function inside the RF, and realize the simple power supply voltage
detection and analysis judgment processing.
Adjust the Tx power dynamically according to the power supply voltage, so as to save the power and
prolong the battery life.
In this mode, the internal MCU of the chip can control the mode of RF part operation register through 3-wire
SPI (PC3/CSB, PC2/SCLK, PC1/SDIO), and to achieve the two Tx modes.
1. Hardware packet Tx mode that fill FIFO through SPI (see Section 2.9 in detail)
The contents that need to be transmitted are filled into the specified registers, which are automatically
transmitted according to the speed, coding mode, number of packets and packet interval, etc. (The data
package format and other relevant information are detailed in Section 2.7 of this chapter).
2. Direct Tx mode that PC0/RFDIN is as the data pin(see Section 2.10 in detail)
That is, the 1-Pin Tx mode, the data stream is generated by the MCU, and the output is carried out by the
specified pin to achieve the most basic work mode of "data entry and antenna out".
Note:
1. The two Tx modes mentioned above are all under the advanced configuration mode, that is, configuring
and operating the chip through SPI.
2. In the advanced configuration mode, RFCTRL needs to be controlled, that is to say, the RFCTRL needs
to be controlled by other pins, so the RFCTRL can not be suspended.
3. The Direct mode which is supported by the advanced configuration mode is similar to the Direct mode of
the simple work mode, by which is controlled by one data pin, but the data input source is different. In the
